molly-guard /mol'ee-gard/ n. [University of Illinois] A shield to prevent tripping of some {Big Red Switch} by clumsy or ignorant hands. Originally used of the plexiglass covers improvised for the BRS on an IBM 4341 after a programmer's toddler daughter (named Molly) frobbed it twice in one day. Later generalized to covers over stop/reset switches on disk drives and networking equipment.